Loader bucket control linkage

ABSTRACT

A control linkage for articularly mounting a loader bucket on a supporting vehicle. The linkage includes a main boom and a secondary boom, with the main boom pivotally mounted on the vehicle and with links connecting the secondary boom to the main boom and with the bucket pivotally mounted on the secondary boom. A hydraulic cylinder is mounted on the vehicle and is connected to the main boom for raising and lowering the bucket, and another hydraulic cylinder is connected with the bucket for tipping the bucket. The linkage and boom pivot mounting are arranged so that the bucket can be raised in a flatened curve and so that the bucket is in an optimum forward position when raised, and the operator has maximum visability of the bucket. That is, the boom is pivoted on the vehicle at a point lower than that required for achieving the raised forward position of the bucket, and thus the operator has improved visability of the bucket.

United States Patent [1 1 Seaberg [2]] Appl. No.: 221,624

[52] US. Cl. 214/776, 214/140 [51] Int. Cl E02f 3/00 [58] Field ofSearch 214/776, DIG. 10,

[56] References Cited UNITED STATES PATENTS 10/1962 Garske 214/776Kromer 214/776 Primary ExaminerGerald M. Forlenza AssistantExaminer-John Mannix Attorney-Arthur J. Hansmann [4 1 July 3,1973

[5 7] ABSTRACT A control linkage for articularly mounting a loaderbucket on a supporting vehicle. The linkage includes a main boom and asecondary boom, with the main boom pivotally mounted on the vehicle andwith links connecting the secondary boom to the main boom and with thebucket pivotally mounted on the secondary boom. A hydraulic cylinder ismounted on the vehicle and is connected to the main boom for raising andlowering the bucket, and another hydraulic cylinder is connected withthe bucket for tipping the bucket. The linkage and boom pivot mountingare arranged so that the bucket can be raised in a flatened curve and sothat the bucket is in an optimum forward position when raised, and theoperator has maximum visability of the bucket. That is, the boom ispivoted on the vehicle at a point lower than that required for achievingthe raised forward position of the bucket, and thus the operator hasimproved visability of the bucket.

10 Claims, 2 Drawing Figures LOADER BUCKET CONTROL LINKAGE Thisinvention relates to control linkage for articularly mounting a loaderbucket on a supporting vehicle and, more particularly, it relates toproviding a loader bucket mounting wherein the operator has optimumvision of the bucket, the bucket is raised to a forwardmost position fordumping the bucket, and the bucket is raised in a relatively flattenedcurve or upright path for minimum required clearance of raising thebucket and for optimum balance of the entire machine.

BACKGROUND OF THE INVENTION The prior art has long been concerned withthe provision of mountings for loader buckets wherein the buckets havethe advantages mentioned in the foregoing paragraph. Many and variedteachings exist to achieve the goal of solving the problems andproviding bucket mountings which have the desired features mentioned.Numbers of patents have issued on the subject of control linkage orbucket mountings, but these patents commonly require that the bucket bemounted on one end of a boom which has its other end pivoted to asupporting vehicle. This then results in the bucket swinging on an arc,the midpoint of which are presents the bucket in an undesirable forwardposition such that the entire machine is unstable, and the single boomtype mounting also has the disadvantage of requiring that the boom bepivoted to the vehicle at a relatively high elevation on the vehicle sothat the bucket can be swung from a low position to a high raisedposition. That type of bucket mounting does not achieve the advantagesmentioned above.. Additionally, a bucket boom is known to be mounted ona supporting vehicle in a manner wherein the boom is not connected tothe vehicle by means of one fixed pivot mounting, but the pivot mountingitself may be movable, such as shown in U. S. Pat. No. 2,538,000.However, that type of construction has the boom which is directlysupporting the bucket mounted to the vehicle at a point high on thevehicle, and, in fact, the point is movable to where it evenapproximates the elevation of the raised bucket, and that type ofconstruction is expensive, complex, and likely to be tempermental in itsfunctioning. Another example of a prior art structure where the boomwhich supports the bucket is not pivoted on the vehicle on a fixed axisis seen in U. S. Pat. No. 3,209,930, but that teaching also requires ahigh mounting for the boom, and the actual physical support of the boomis not a stable one in that it depends entirely upon the swinging of thesupporting links about their respective arcs as shown in that patent.

Accordingly, it is an object of this invention to provide a controllinkage or mounting for a loader bucket onto a vehicle and wherein thelinkage, including the booms, is connected at a low elevation on thevehicle so that the operator has optimum vision of the bucket in itsworking positions.

Still another object of this invention is to provide control linkage ora mounting for a loader bucket and wherein the bucket can be positionedin a forwardmost position when the bucket is raised, and this is forpurposes of dumping the bucket into a truck or any other dump spot. Inaccomplishing this object, it will be understood that the bucket doesnot simply swing about a fixed axis on the vehicle, but the bucketactually is positioned beyond the arc which would otherwise be scribedif the bucket were supported on a boom fixed to the vehicle.

Still another object of this invention is to accomplish any or all ofthe aforementioned objectives, and to do so with a bucket controllinkage or mounting which is of maximum sturdy character to supportmaximum loads without overbalancing the machine, and to do so with aminimum of parts and without complicated parts which are not reliable inoperation.

Other objects and advantages will become apparent on reading thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of acontrol linkage of this invention, and showing the linkage in the raisedposition in dotted lines, and also showing the supporting vehicle indot-dash lines.

FIG. 2 is a schematic view of the control linkage shown in FIG. 1, on aslightly enlarged scale, and also showing the position of the linkage inthe raised position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings indicate atractor type of vehicle 10 which is shown in dot-dash lines, and theloader bucket 11 is articularly mounted on the vehicle 10 by means ofthe mounting or control linkage generally designated 12. The linkage 12includes a main boom 13 and a secondary boom 14, and the two booms arearticularly connected together by means described later. The boom or arm13 is pivotally mounted at one end theref on the vehicle 10 and at afixed pivot pin or the like 16. Lift means inrthe showing of ahydraulically powered cylinder 17 is connected to the vehicle at a pin18 and is connected to the boom 13 at a pin 19. Thus the extension andcontraction of the hydraulic cylinder unit 17 will cause the pivotaction of the boom 13 about its fixed mounting pin 16.

A first link 18 and a second link 19 are articularly connected to thebooms l3 and 14 by connecting pins 21 and 22, on the link 18 andconnecting pins 23 and 24, on the link 19. Thus the links 18 and 19 aredescribed as being connected to the end of the boom 13 opposite from theboom end 26 where the pivot 16 is located. Likewise, the links 18 and 19are connected to the secondary boom 14 at the end of the boom 14opposite from the boom end where the bucket 11 is located, and it willbe seen that the bucket 1 1 is pivotally mounted on the end 27 of theboom 14 by means of the pivot pin 28.

Thus the links 18 and 19 and the booms l3 and 14 present a four-bar orparallelogram linkage, as shown. To stabilize that linkage, the link 18has its lower end 29 extending downwardly to where it connects to a link31 through a pin 32. In turn, the link 31 is pivoted on the vehicle 10at the pivot pin 33 which is fixed relative to the vehicle 10.

With the control linkage described thus far, it will now be understoodthat identical linkage exists on the opposite side of the vehicle 10,and the linkage is swingable or pivotal about the fixed pins 16 and 33,for raising and lowering the bucket 11. Thus, from the solid lineposition shown in FIG. 1, the control linkage thus far described can bemoved into the raised position shown by the dotted lines. When thebucket 1.1 is

raised as indicated, it' will be noticed and understood that the bucket11 is essentially as far forward in the raised position as it is in thelowered position shown in FIG. 1, even though the pivot mountings 16 and33 are substantially closer to the elevation of the bucket in thelowered position. This is one desirable feature of this control linkagein that the bucket 11 can then be dumped over a truck or any other dumpsite which requires that the bucketbe high but as far forward as isneeded or as is required for stability of the entire machine.

In connection with the feature of the forward position of the bucket 11when the bucket is raised, FIG. 2, in dotted lines, shows the bucket 11in lhe raised position, and it also shows an are 34 which traces theswing of the bucket 11 from its lowered solid-line position to itsraised dotted line position, and the arc 34 has a center marked C on thevehicle 10. That is, to achieve the forward raised position for thebucket 11 by virtue of a single boom, or like bucket mounting, themounting would have to be as high as the center designated C in FIG. 2.That height or elevation of location for center C affects the stabilityof the machine, and it interferes with the operators visability of thebucket and the material being handled by the bucket, since the center Cis too high on the vehicle 10, and of course that center C is above themounting point 16.

Further, FIG. 2 shows the bucket in the substantially half way orhorizontal position of lift, by location of the bucket pin 28, and itwill again be noted that the pin 28 is inside the are 34 and thereforethe bucket 11 does not require the large swing of the path as designatedby the are 34, but instead the bucket 11 follows the flatter curve ofswing and this provides for the desirable flat or somewhat vertical liftof the bucket 11.

Another observation is that if the bucket 11 were pivoted on the vehicleabout one fixed pivot point and through one boom connected to that pivotpoint and to the bucket 11, that boom would then have the bucket pin 28scribe the are designated 36 in FIG. 2. It will then be understood thatthe are 36 would not cause the bucket to be positioned in its desiredand actual raised and forwardmost position as shown in FIGS. 1 and 2.The arc 36 is struck about the lower fixed pivot point 16, so that whilethat arrangement would provide for the desired lower mounting of theboom, it would not position the bucket 11 in the forwardmost position asdescribed.

To understand the forward position of the raised bucket 11, observationis made of the link 18 and its control link 31. Thus, from the loweredposition and the orientation of link 18, the raising of the link 18 doesnot cause the link 18 to become vertically disposed, to say nothing ofcausing it to be oriented to tilt rearwardly at the top. Instead, thelink 18 is oriented to tilt forwardly at the top and in the raisedposition, and this positions the secondary boom 14 to a forwardposition. Therefore, the fixed pivot point 33 is located rearwardly andat an elevation lower than the location of the fixed pivot 16.

The bucket has a tilt control which includes a hydraulic cylinder 41which is connected to the upper end of the-link 18 through the pin 42. Alink 43 is pivoted at its lower end on a pin 44 on the secondary boom14, and the ram end of the cylinder 41 is connected to the link 43through a pin 46. Finally, a link 47 is connected to the upper end ofthe link 43 through a pin 48 and is connected to the bucket 11 through apin 49. Thus there is an articular connection between the controllinkage described and the bucket 11 for the tilt action of the bucket11. Further, the arrangement described in connection with the articularconnectors for tilting the bucket is such that the bucket will remain atleast substantially horizontal or in the same attitude, whether or notthat be horizontal, when the cylinder 41 is not operating but when thelift cylinder 17 is operated so that the bucket is swung from thelowered position to a raised position, all as indicated in FIG. 1. Ofcourse FIG. 2 shows the cylinder unit 41 somewhat extended so that thebucket 11 is tipped somewhat forward and may be considered to be in adigging position when it is in the lower position in FIG. 1, and it hassubstantially the same position when it is raised, as seen in FIG. 1,though the cylinder 41 had not been extended or contracted.

The links and booms described may exist, and preferably do, on each sideof the vehicle 10, in the known arrangement of control linkage orsupport means for a loader bucket of this nature. Also, the boom or arms13 may be connected by a cross shaft extending across the vehicle 10 toprovide more frame stability, if suchbe necessary or desirable. Also,the control linkage or structure described achieves the result of a highlift for the bucket 1 1 though there is a low profile or mounting of thelinkage relative to the vehicle 10, and, the bucket in the liftedposition is substantially directly above the bucket in the loweredposition, and that lift position is the forward positon described. Itwill also be noticed that the one link 18 has an action which is notalong an arcuate path about either fixed pivot mounting 16 or 33, withrespect to the upper end of the one link 18, and, in fact, the link 18moves substantially vertically upwardly rather than rotate about a pivotaxis. Also, the pivot mounting 33 is lower than the elevation of themounting 16, and it is rearwardly thereof relative to the vehicle 10.Still further, the arc scribed by the articular connection pin 22 issuch that it is crossed by the arc scribed by the articular connection32 when the bucket is lifted, so the link 18 has the action mentioned.That is, the connection pin 32 is rearward of .the pin 22 even when thebucket is in the raised position, as shown by the dotted lines in FIG. 1and as shown by the pin locations in FIG. 2.

What is claimed is:

1. Control linkage for articularly mounting a loader bucket on asupporting vehicle, comprising a main boom vertically pivotally mountedat one end thereof on said vehicle, a lift means operatively connectedwith said main boom for vertically pivoting said main boom, a secondaryboom having one end articularly connected with said bucket, two linksarticularly connected between said booms and forming a four-bar linkagewith said booms, an additional link pivotally mounted on said vehicleand articularly connected with one of said two links for controlling theattitude of said one link throughout the raising and lowering of saidbucket, and bucket pivot-control means connected to said bucket forcontrolling the pivot of said bucket on said secondary boom in loadingand unloading of said bucket.

2. The control linkage as claimed in claim 1, wherein said main boom isdisposed at an elevation below that of said secondary boom.

3. The control linkage as claimed in claim 2, wherein said one linkextends downwardly to an elevation below that of the pivot mounting ofsaid main boom, and the articulate connection between said one link andsaid additional link being at said elevation on said one link.

4. The control linkage as claimed in claim 3, wherein said bucketpivot-control means is articularly connected with said one link.

5. The control linkage as claimed in claim 1, wherein said bucketpivot-control means is articularly connected with said secondary boom.

6. The control linkage as claimed in claim 1, wherein said booms arearticularly connected together by said two links being connected to saidbooms at the respective ends thereof opposite said one ends of each saidbooms.

7. The control linkage as claimed in claim 6, wherein said one link andsaid bucket pivot-control means are articularly connected together, andsaid lift means and said bucket pivot-control means are hydrauliccylinder units.

8. The control linkage as claimed in claim 6, wherein the pivot mountingof said additional link is disposed at a location to cause the end ofsaid one link opposite its said one end to move substantially upwardly,rather than in a true arcuate path, during the lifting of said bucket.

9. The control linkage as claimed in claim 8, wherein said location isat an elevation lower than that of the pivot mounting of said main boom.

10. The control linkage as claimed in claim 9, wherein said pivotmountings of said main boom and said additional link, and theirrespective articular connections with said one link, are located to havethe arc of movement of said articular connection for said additionallink cross the arc of movement of said articular connection for saidmain boom, in the lifting of said bucket.

1. Control linkage for articularly mounting a loader bucket on asupporting vehicle, comprising a main boom vertically pivotally mountedat one end thereof on said vehicle, a lift means operatively connectedwith said main boom for vertically pivoting said main boom, a secondaryboom having one end articularly connected with said bucket, two linksarticularly connected between said booms and forming a four-bar linkagewith said booms, an additional link pivotally mounted on said vehicleand articularly connected with one of said two links for controlling theattitude of said one link throughout the raising and lowering of saidbucket, and bucket pivot-control means connected to said bucket forcontrolling the pivot of said bucket on said secondary boom in loadingand unloading of said bucket.
 2. The control linkage as claimed in claim1, wherein said main boom is disposed at an elevation below that of saidsecondary boom.
 3. The control linkage as claimed in claim 2, whereinsaid one link extends downwardly to an elevation below that of the pivotmounting of said main boom, and the articulate connection between saidone link and said additional link being at said elevation on said onelink.
 4. The control linkage as claimed in claim 3, wherein said bucketpivot-control means is articularly connected with said one link.
 5. Thecontrol linkage as claimed in claim 1, wherein said bucket pivot-controlmeans is articularly connected with said secondary boom.
 6. The controllinkage as claimed in claim 1, wherein said booms are articularlyconnected together by said two links being connected to said booms atthe respective ends thereof opposite said one ends of each said booms.7. The control linkage as claimed in claim 6, wherein said one link andsaid bucket pivot-control means are articularly connected together, andsaid lift means and said bucket pivot-control means are hydrauliccylinder units.
 8. The control linkage as claimed in claim 6, whereinthe pivot mounting of said additional link is disposed aT a location tocause the end of said one link opposite its said one end to movesubstantially upwardly, rather than in a true arcuate path, during thelifting of said bucket.
 9. The control linkage as claimed in claim 8,wherein said location is at an elevation lower than that of the pivotmounting of said main boom.
 10. The control linkage as claimed in claim9, wherein said pivot mountings of said main boom and said additionallink, and their respective articular connections with said one link, arelocated to have the arc of movement of said articular connection forsaid additional link cross the arc of movement of said articularconnection for said main boom, in the lifting of said bucket.